Component Tools

makeAssistantTool and useAssistantTool are deprecated compatibility APIs, documented here for reference only. New code should define a toolkit — see Defining Tools and Migrating Tools to Toolkits.

API Reference

makeAssistantTool

Deprecated. Use a toolkit with Tools({ toolkit }) and register it via useAui({ tools: Tools({ toolkit }) }) instead. See https://assistant-ui.com/docs/migrations/toolkit-tools.

Creates a React component that registers an assistant tool when rendered.

Use this when exporting reusable tool modules that can be included in JSX rather than calling useAssistantTool directly.

type AssistantToolProps = CoreAssistantToolProps<TArgs, TResult> & {
  /** Component used to render calls to this tool in assistant messages. */
  render?: ToolCallMessagePartComponent<TArgs, TResult> | undefined;
  /** Lightweight text rendered while a tool call is running or complete. */
  renderText?: ToolCallText<TArgs, TResult> | undefined;
};

const makeAssistantTool: <TArgs extends Record<string, unknown>, TResult>(tool: AssistantToolProps<TArgs, TResult>) => AssistantTool;

useAssistantTool

Deprecated. Use a toolkit with Tools({ toolkit }) and register it via useAui({ tools: Tools({ toolkit }) }) instead. See https://assistant-ui.com/docs/migrations/toolkit-tools.

Registers a tool with the assistant model context while the component is mounted.

If render is provided, it is also installed as the renderer for matching tool-call message parts. The registration is removed automatically when the component unmounts or the tool definition changes.

Pass a referentially stable tool object, such as one declared at module scope or memoized with useMemo, to avoid re-registering on every render.

const weatherTool = {
  toolName: "get_weather",
  type: "frontend",
  description: "Get the weather for a city.",
  parameters: weatherSchema,
  execute: async ({ city }: { city: string }) => fetchWeather(city),
  render: WeatherToolUI,
} satisfies AssistantToolProps<{ city: string }, Weather>;

function WeatherToolRegistration() {
  useAssistantTool(weatherTool);
  return null;
}

useAssistantTool

tool : AssistantToolProps<TArgs, TResult>

streamCalldeprecated ?: ToolStreamCallFunction<TArgs, TResult>

Deprecated: Experimental, API may change.

display ?: ToolDisplay

How this tool's UI is presented relative to the chain-of-thought trace. Defaults to `"inline"` (folded into the chain-of-thought grouping). Set `"standalone"` to surface the tool call on its own. `human` tools are always `"standalone"` and cannot opt out.

unstable_backendDefaultunstable ?: AssistantToolProps["unstable_backendDefault"]

parameters ?: boolean

type ?: "mcp"

Tools loaded from an MCP server by a server adapter.

description ?: undefined

Natural-language description shown to the model when selecting tools.

parameters ?: undefined

Schema for the arguments the model must provide when calling the tool.

disabled ?: boolean

Prevents the tool from being exposed to the model while true.

execute ?: undefined

Executes the tool after the model provides valid arguments.

toModelOutput ?: undefined

Converts the execution result into model-visible output.

experimental_onSchemaValidationError ?: undefined

Handles invalid tool arguments when schema validation fails.

providerOptions ?: undefined

toolName : string

render ?: unknown

Component used to render calls to this tool in assistant messages.

renderText ?: ToolCallText<TArgs, TResult>

Lightweight text rendered while a tool call is running or complete.

running ?: ToolCallRunningText<TArgs>
complete ?: ToolCallCompleteText<TArgs, TResult>